Liquid crystal display device and manufacturing method of liquid crystal display device

ABSTRACT

To sophisticate a portable electronic appliance without hindering reduction of the weight and the size, more specifically, to sophisticate a liquid crystal display apparatus installed in a portable electronic appliance without hindering the mechanical strength, a liquid crystal display apparatus includes a first plastic substrate, a light-emitting device which is disposed over the first plastic substrate, resin which covers the light-emitting device, an insulating film which is in contact with the resin, a semiconductor device which is in contact with the insulating film, a liquid crystal cell which is electrically connected to the semiconductor device, and a second plastic substrate, wherein the semiconductor device and the liquid crystal cell are disposed between the first plastic substrate and the second plastic substrate.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a liquid crystal displayapparatus, and more particularly such a transparent liquid crystaldisplay apparatus installed in a portable electronic appliance. Further,the invention relates to a method for manufacturing a liquid crystaldisplay apparatus, and more particularly such a method for manufacturinga transparent liquid crystal display apparatus installed in a portableelectronic appliance. Moreover, the invention relates to an electronicappliance using the liquid crystal display apparatus.

[0003] 2. Related Art

[0004] A portable electronic appliance as typified by a portable phoneor an electronic book is required to have various functions such assending and receiving mail, recognizing sound, and capturing an imageusing a small camera, in addition to a flat panel display for displayingan image. On the other hand, there is still a strong demand by user suchas reducing size and weight. Therefore there is a need for installing IChaving further large size of circuit or amount of memory as much aspossible into limited volume of a portable electronic appliance.

[0005] It is important how to manufacture a flat panel display into thinand light in order to keep space to accommodate IC and to reduce sizeand weight of a portable electronic appliance. For instance, a liquidcrystal display apparatus used relatively a lot for a portableelectronic appliance can be in some degree reduced its size and weightby reducing a thickness of a glass substrate used for a panel filledwith liquid crystal and by adopting a reflective type liquid crystaldisplay apparatus that needs no light source, an optical waveguide, orthe like.

[0006] However, a glass substrate cannot be formed into too thinconsidering mechanical strength of a panel. For instance, in case ofusing barium borosilicate glass, alumino borosilicate glass, or thelike, thickness limit and weight limit of 3-inch-square is at most from1 to 2 mm and 10 g, respectively. A reflective type liquid crystaldisplay apparatus utilizing outside light is difficult in recognition ofan image in the dark so that an advantage that a portable electronicappliance is not required to be site-specific is not sufficientlyutilized.

SUMMARY OF THE INVENTION

[0007] It is an object of the present invention is to sophisticate aportable electronic appliance without hindering reduction of the weightand the size. It is more specific object of the invention is tosophisticate a liquid crystal display apparatus installed in a portableelectronic appliance without hindering the mechanical strength.

[0008] A liquid crystal display apparatus according to the inventionuses a light-emitting device such as a light-emitting diode (LED) or anelectroluminescent device as a light source. The light-emitting deviceformed over a plastic substrate having flexibility is covered with aresin that is transparent to light in order to flatten a surface of thelight-emitting device. Then, a liquid crystal cell and a semiconductordevice for driving the liquid crystal cell are provided over theflattened resin. A light source in a state that a light-emitting deviceis covered with a resin is referred to as a solid-state light source.

[0009] Generally, a plastic substrate is superior in mechanical strengthfor vibration and shock by its flexibility so that the thickness caneasily be reduced. However, a plastic substrate and a resin often havenot enough heat resistance to withstand heat treatment in manufacturinga semiconductor device used for a liquid crystal display apparatus. Inview of this, according to the invention, a semiconductor device isformed over a substrate having resistance enough to withstand the heattreatment, and the semiconductor device is moved over a solid-statelight source.

[0010] A liquid crystal display apparatus according to the invention isprovided with a means of reflecting light generated in a light-emittingdevice in a direction of a liquid crystal cell. Specifically, light isreflected by pasting a ready-made reflection plate over the plasticsubstrate or by depositing a metal film (hereinafter, reflection film)over a surface of the plastic substrate by vapor deposition. Further, apolarization plate is provided between a resin covering a light-emittingdevice, and a semiconductor device and liquid crystal cell.

[0011] Hereinafter, the first method for manufacturing a liquid crystaldisplay apparatus according to the invention will be explained inspecific.

[0012] A first substrate that has heat resistance capable ofwithstanding heat treatment in a process for manufacturing asemiconductor device is prepared. A metal film is formed over the firstsubstrate, and oxidized to form a metal oxide film having an extremethin film thickness of several nm. Then, an insulating film and asemiconductor film are sequentially stacked over the metal oxide film.The insulating film can be formed into either a single layer or alaminated layer composed of a plurality of films. For instance, siliconnitride, silicon oxynitride, silicon oxide, or the like can be used forthe insulating film. A semiconductor device used for a liquid crystaldisplay apparatus is formed by the semiconductor film.

[0013] After the semiconductor device is formed and before completing aliquid crystal cell, a second substrate is pasted onto the firstsubstrate to cover the semiconductor device in such a way that thesemiconductor device is sandwiched between the second substrate and thefirst substrate. The liquid crystal cell includes a pixel electrode, acounter electrode, and liquid crystal disposed between the pixelelectrode and the counter electrode. As used herein, the term “beforecompleting a liquid crystal cell” refers to a period between theformation of a pixel electrode of a liquid crystal cell connectedelectrically to a TFT, which is one of semiconductor devices, and anorientation film covering the pixel electrode, and the paste of acounter substrate provided with a counter electrode.

[0014] A third substrate is pasted for reinforcing rigidity of the firstsubstrate onto an opposite side of the first substrate on which thesemiconductor device is formed. The first substrate can be easilyseparated and the semiconductor device is hardly damaged when rigidityof the first substrate is stronger than that of the second substrate. Inaddition, the third substrate is unnecessary to be pasted in case thatrigidity of the first substrate is enough to separate the firstsubstrate from the semiconductor device.

[0015] Then, the metal oxide film is crystallized by heat treatment orthe like to enhance brittleness of the metal oxide film and to make iteasier for the first substrate to be easily separated from thesemiconductor device. Subsequently, the first substrate is separatedtogether with the third substrate from the semiconductor device. Inaddition, the heat treatment to crystallize the first substrate can becarried out before pasting either the third substrate or the secondsubstrate. Alternatively, the heat treatment in a process for formingthe semiconductor device can serve as the heat treatment to crystallizethe metal oxide film.

[0016] The first substrate may be separated together with the thirdsubstrate from the semiconductor device by splitting-off a boundary faceof the metal film and the metal oxide film, the boundary face of theinsulating film and the metal oxide film, or metal oxide film itself. Inany case, the first substrate is separated so as the semiconductordevice to attach to the second substrate.

[0017] A plastic substrate at the side of a light source is prepared forbeing pasted with a semiconductor device. Hereinafter, the plasticsubstrate is referred to as a device substrate to distinguish from aplastic substrate at the side of a counter electrode used in later. Alight-emitting device is provided over the device substrate, and a resinis coated to cover the light-emitting device. Then, a first polarizationplate is pasted onto the resin that is flattened.

[0018] Next, by separating the first substrate, the semiconductor deviceattached to the second substrate is pasted onto the first polarizationplate with adhesive or the like. Then, the second substrate is separatedto fix the semiconductor device to the device substrate.

[0019] A liquid crystal cell for a liquid crystal apparatus is formed.Specifically, a plastic substrate provided with a counter electrode, asecond polarization substrate, or the like (hereinafter, countersubstrate) is prepared separately, and pasted onto the semiconductordevice, then, a liquid crystal cell is completed. A color filter, anorientation film, a black matrix, and the like may be provided to thecounter substrate in addition to the counter electrode and the secondpolarization plate.

[0020] Hereinafter, a second method for manufacturing a liquid crystaldisplay apparatus according to the invention will be explained.

[0021] A first substrate that has heat resistance capable ofwithstanding heat treatment in a process for manufacturing asemiconductor device is prepared. A metal film is formed over the firstsubstrate, and oxidized to form a metal oxide film having an extremethin film thickness of several nm. Then, an insulating film and asemiconductor film are sequentially stacked over the metal oxide film.The insulating film can be either a single layer or a laminated layerhaving a plurality of films. For instance, silicon nitride, siliconoxynitride, silicon oxide, or the like can be used for the insulatingfilm. A semiconductor device used for a liquid crystal display apparatusis formed by the semiconductor film.

[0022] A liquid crystal cell for a liquid crystal apparatus is formed.The liquid crystal cell includes a pixel electrode, a counter electrode,and liquid crystal disposed between the pixel electrode and the counterelectrode. Specifically, a plastic substrate provided with a counterelectrode, a second polarization substrate, or the like (hereinafter,counter substrate) is prepared separately, and pasted onto thesemiconductor device, then, a liquid crystal cell is completed. A colorfilter, an orientation film, a black matrix, and the like may beprovided to the counter substrate in addition to the counter electrodeand the second polarization plate.

[0023] After forming the semiconductor device and the liquid crystalcell, a second substrate is pasted onto the semiconductor device and theliquid crystal cell so as to cover them. Accordingly, the liquid crystalcell is interposed between the first substrate and the second substrate.

[0024] A third substrate is pasted for reinforcing rigidity of the firstsubstrate onto an opposite side of the first substrate on which thesemiconductor device and the liquid crystal cell are formed. The firstsubstrate can be easily separated and the semiconductor device and theliquid crystal cell are hardly damaged when rigidity of the firstsubstrate is stronger than that of the second substrate. In addition,the third substrate is unnecessary to be pasted in case that rigidity ofthe first substrate is enough to be separated from the semiconductordevice.

[0025] Then, the metal oxide film is crystallized by heat treatment orthe like to enhance brittleness of the metal oxide film and to make iteasier for the first substrate to be easily separated form thesemiconductor device. Subsequently, the first substrate is separatedtogether with the third substrate from the semiconductor device. Inaddition, the heat treatment to crystallize the first substrate can becarried out before pasting either the third substrate or the secondsubstrate. Alternatively, the heat treatment in a process for forming asemiconductor device can serve as the heat treatment to crystallize themetal oxide film.

[0026] The first substrate may be separated together with the thirdsubstrate from the semiconductor device and the liquid crystal cell bysplitting-off a boundary face of the metal film and the metal oxidefilm, the boundary face of the insulating film and the metal oxide film,or metal oxide film itself. In any case, the first substrate isseparated so as the semiconductor device and the liquid crystal cell toattach to the second substrate.

[0027] A plastic substrate at the side of a light source (devicesubstrate) is prepared for being pasted with the semiconductor deviceand the liquid crystal cell. A light-emitting device is provided overthe device substrate, and a resin is coated to cover the light-emittingdevice. Then, a first polarization plate is pasted onto the resin thatis flattened.

[0028] Next, by separating the first substrate, the semiconductor deviceand the liquid crystal cell attached to the second substrate is pastedonto the first polarization plate with adhesive or the like. Then, thesecond substrate is separated to fix the semiconductor device to thedevice substrate. And then, a liquid crystal display apparatus iscompleted.

[0029] In case that a plurality of liquid crystal display apparatus isformed from one large substrate, the large substrate is diced to divideinto the plurality of liquid crystal display apparatus.

[0030] According to the invention, a thickness of a liquid crystaldisplay apparatus can be at least 0.6 mm and at most 1.5 mm.

[0031] As described above, the liquid crystal display apparatus issuperior in mechanical strength for shock since the device substrate andthe counter substrate have flexibility compared with a glass substrate.Consequently, a thickness of the liquid crystal display apparatus caneasily be reduced. Further, the freedom of shape of the liquid crystaldisplay apparatus is increased since the device substrate and thecounter substrate have flexibility. Therefore a liquid crystal displayapparatus can be formed into a curved shape to be capable of pastingonto a kind of a columned bottle.

[0032] Light generated in the light-emitting device is dispersed bycovering the light-emitting device with a resin that is transparent tolight to equalize brightness of a pixel portion of a liquid crystaldisplay apparatus. Brightness can be further equalized by providingdispersion plate between a liquid crystal cell and a resin covering alight-emitting device.

[0033] According to the invention, a liquid crystal display apparatuscan be drastically formed into thin and reduced its weight without beingdamaged the mechanical strength by above described structure. Applying aliquid crystal display apparatus according to the invention to anelectronic appliance, a space for using IC can be kept large and anelectronic appliance can be sophisticated without preventing theelectronic appliance from being lightweight and downsized. Especially, aliquid crystal display apparatus according to the present invention isuseful for a portable electronic appliance since usability thereofbecomes improved by reducing the weight and the size. According to theinvention, even when size of a pixel portion of a liquid crystal displayapparatus is increased, weight thereof is almost same as that of aliquid crystal display apparatus using a conventional glass substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034]FIGS. 1A to 1D are views showing cross-sectional views of a liquidcrystal display apparatus according to the invention;

[0035]FIGS. 2A to 2D are views showing cross-sectional views of a liquidcrystal display apparatus according to the invention;

[0036]FIGS. 3A to 3C are explanatory views showing a method formanufacturing a liquid crystal display apparatus according to theinvention;

[0037]FIGS. 4A to 4C are explanatory views showing a method formanufacturing a liquid crystal display apparatus according to theinvention;

[0038]FIGS. 5A and 5B are explanatory views showing a method formanufacturing a liquid crystal display apparatus according to theinvention;

[0039]FIG. 6 is an explanatory view showing a method for manufacturing aliquid crystal display apparatus according to the invention;

[0040]FIGS. 7A to 7C are explanatory views showing a method formanufacturing a liquid crystal display apparatus according to theinvention;

[0041]FIGS. 8A and 8B are explanatory views showing a method formanufacturing a liquid crystal display apparatus according to theinvention;

[0042]FIGS. 9A and 9B are explanatory views showing a method formanufacturing a liquid crystal display apparatus according to theinvention;

[0043]FIG. 10 is an explanatory view showing a method for manufacturinga liquid crystal display apparatus according to the invention;

[0044]FIGS. 11A and 11B are explanatory views showing a method formanufacturing a liquid crystal display apparatus according to theinvention;

[0045]FIGS. 12A to 12C are cross-sectional views showing a thin filmcircuit or an LED driver thin film circuit;

[0046]FIGS. 13A to 13D are cross-sectional views showing an electroniccard utilizing a liquid crystal display apparatus according to theinvention;

[0047]FIG. 14 is an oblique perspective view showing a large devicesubstrate;

[0048]FIG. 15 is a view showing an LED utilizing an FPC and the statethat the LED is pasted onto a device substrate;

[0049]FIGS. 16A and 16B are views showing the structure of a devicesubstrate;

[0050]FIGS. 17A and 17B are an oblique perspective view and across-sectional view showing a sensor electronic card, respectively;

[0051]FIGS. 18A to 18F are views showing electronic appliances;

[0052]FIGS. 19A and 19B are cross sections of TEM images of a metaloxide film before separating;

[0053]FIGS. 20A and 20B are cross sections of TEM images of aninsulating film after separating; and

[0054]FIGS. 21A and 21B are cross-sectional views showing a liquidcrystal display apparatus according to the present invention.

[0055] These and other objects, features and advantages of the presentinvention will become more apparent upon reading of the followingdetailed description along with the accompanied drawings.

DETAILED DESCRIPTION OF THE INVENTION

[0056] The structure of a liquid crystal display apparatus according tothe present invention will be explained with reference to FIGS. 1A to1D. FIG. 1A is a cross-sectional view of a device substrate 101 beforesemiconductor device is pasted to the device substrate. FIG. 1B is a topsurface view of the device substrate 101 illustrated in FIG. 1A. FIG. 1Ais a cross-sectional view of the device substrate 101 illustrated inFIG. 1B taken along the line A-A′.

[0057] The device substrate 101 illustrated in FIGS. 1A and 1B has aconcave portion 102. One or a plurality of LED 103 is provided in theconcave portion 102. The concave portion 102 can be formed by a knownmeans, for example, a mold. The driving of the LED 103 is controlled bya thin film circuit (hereinafter, LED driver thin film circuit) 104 fordriving the LED 103. The LED driver thin film circuit 104 is not alwaysnecessary to be provided in the concave portion 102, that is, the LEDdriver thin film circuit 104 can be provided except the concave portion102. The way of forming the LED driver thin film circuit 104 will bedescribed later.

[0058] Reference numeral 105 denotes a wiring formed over the devicesubstrate 101. The wiring 105 connects electrically the LED 103 to theLED driver thin film circuit 104, and also connects electrically the LEDdriver thin film circuit 104 to a semiconductor device pasted later toan exterior of the liquid crystal display apparatus. The wiring 105 canbe formed over the device substrate 101 by a known means such asplating.

[0059] Reference numeral 106 denotes a reflection film that is formed bydepositing metals by vapor deposition in the concave portion 102. Toprevent short-circuiting, the reflection film 106 is deposited to beelectrically separated from the wiring 105 or the LED 103. In thisembodiment, as a means for reflecting light emitted from the LED 103 inthe direction of a liquid crystal cell, a reflection film that is formedby vapor deposition is used, however, a reflection plate that is formedseparately may be pasted onto the device substrate 101. In this case,the reflection plate is preferably pasted onto the position so as toreflect light emitted from the LED 103 in the direction of a liquidcrystal cell. For instance, the reflection plate can be provided oversurface that is opposing to the LED 103 and that is not provided withthe concave portion 102.

[0060] The LED 103 is covered with a resin 107. In this embodiment, theresin 107 fills the concave portion 102. In case that the LED driverthin film circuit 104 is provided in the concave portion 102, the LEDdriver thin film circuit 104 is covered with the resin 107. As the resin107, known resin such as acrylic resin, epoxy resin, urethane resin,polycarbonate resin, or vinyl resin can be used. Transparent particleshaving different refractive index from that of the resin can bedispersed in the resin 107. For instance, spherical particles can bedispersed in polymethyl methacrylate resin. It is desired that resin beappropriately selected according to the pasting process of asemiconductor device.

[0061] In FIGS. 1A and 1B, reference numeral 108 denotes a light sourceportion that is provided with the LED 103 and the reflection film 106,and that is covered with the resin 107.

[0062]FIG. 1C is a cross-sectional view of the liquid crystal displayapparatus according to the invention in which a semiconductor device ispasted and a liquid crystal cell is completed. FIG 1D is a top view ofthe liquid crystal display apparatus illustrated in FIG. 1C. FIG 1C is across-sectional view of FIG. 1D taken along the line of B-B′.

[0063] A semiconductor device 110 is pasted to the resin 107 by anadhesive 109. Not shown in FIG. 1C, a first polarization plate isprovided between the resin 107 and the adhesive 109. In this embodiment,as shown in FIGS. 1C and 1D, the semiconductor device 110 is not onlyused to a pixel portion of a liquid crystal display apparatus but alsoused to a thin film circuit 111 for driving or signal processing aliquid crystal display apparatus.

[0064] Reference numeral 113 denotes a counter substrate that isencapsulated with liquid crystal 112 by a sealant 114. The region wherethe liquid crystal 112 is encapsulated by the counter substrate 113corresponds to a panel 115. Light from the light source portion 108 isradiated to a pixel portion 116 provided to the panel 115. In addition,the thin film circuit 111 is electrically connected to the wiring 105 bywire bonding method, flip chip method, or the like.

[0065] According to this embodiment, signals or power source voltage canbe supplied to a liquid crystal display apparatus via the wiring 105,but not exclusively, signals or power source voltage may be supplied bylight using a light-emitting device, a light sensor, or the like, or byelectromagnetic induction using an antenna coil.

[0066] As a plastic substrate, ARTON® containing norbornene resin withpolar group by JSR Corporation can be used. In addition, a plasticsubstrate such as polyethylene terephthalate (PET), polyether sulfone(PES), polyethylene naphthalate (PEN), polycarbonate (PC), nylon,polyether ether ketone (PEEK), polysulfone (PSF), polyetherimide (PEI),polyalylate (PAR), polybutylene terephthalate (PBT), or polyimide can beused.

[0067] An example that a concave portion is provided to a devicesubstrate and an LED is provided in the concave portion is explained inthis embodiment, however, the invention is not limited thereto. A flatplastic substrate without concave portion can be used as the devicesubstrate.

[0068] A structure of the liquid crystal display apparatus that utilizesa flat plastic substrate as a device substrate will be explained withreference to FIGS. 2A to 2D. FIG. 2A is a cross-sectional view of adevice substrate in which a semiconductor device has not pasted yet. Thedevice substrate 201 is flat and not provided with a concave portion.FIG. 2B is a top view of the device substrate 201 illustrated in FIG.2A. FIG. 2A is a cross-sectional view of FIG. 2B taken along the lineA-A′.

[0069] One or a plurality of LED 203 is provided over the devicesubstrate 201 illustrated in FIGS. 2A and 2B. Reference numeral 204denotes an LED driver thin film circuit. The LED driver thin filmcircuit 204 is electrically connected to the LED 203 by a wiring 205.The wiring 205 is used for electrically connecting the LED driver thinfilm circuit 204 or a semiconductor device, which is formed later, toexterior of the liquid crystal display apparatus. To preventshort-circuiting, a reflection film 206 is deposited to be separatedfrom the wiring 205 and the LED 203. A reflection film that is formedseparately can be used instead of that formed by vapor deposition.

[0070] The LED 203 is covered with a resin 207. In this embodiment, aphotosensitive resin is coated and partly exposed, then, the resin 207is coated in order to expose a part of the wiring 205. The LED driverthin film circuit 204 may also be covered with the resin 207. In FIGS.2A and 2B, reference numeral 208 denotes a light source portion that isprovided with the LED 203 and the reflection film 206, and that iscovered with the resin 207.

[0071]FIG. 2C is a cross-sectional view of a liquid crystal displayapparatus according to the invention in which a semiconductor device ispasted and a liquid crystal cell is completed. FIG. 2D is a top view ofthe liquid crystal display apparatus illustrated in FIG. 2C. FIG. 2C isa cross-sectional view of FIG. 2D taken along the line of B-B′.

[0072] A semiconductor device 210 is pasted onto the resin 207 by anadhesive 209. Not shown in FIG. 2C, a first polarization plate isprovided between the resin 207 and the adhesive 209. In addition,reference numeral 211 corresponds to a thin film circuit formed usingthe semiconductor device 210.

[0073] Reference numeral 213 denotes a counter substrate that isencapsulated with liquid crystal 212 by a sealant 214. The region wherethe liquid crystal 212 is encapsulated by the counter substrate 213corresponds to a panel 215. Light from the light source portion 208 isradiated to a pixel portion 216 provided with the panel 215. Inaddition, the thin film circuit 211 is electrically connected to thewiring 205 by wire bonding method, flip chip method, or the like.

[0074] The concave portion of the device substrate allows the LED to becovered with a resin while wiring is exposed by only dropping a resininto the concave portion. Further, a reflection film in the concaveportion allows light emitted from LED to radiate effectively to thepixel portion. In case that the concave portion is not provided, theintensity of the device substrate can be further increased compared withthe case that the concave portion is provided.

[0075] Then, a specific method for manufacturing a semiconductor deviceused for the thin film circuit and the liquid crystal display apparatusand a way of pasting the semiconductor device onto the device substratewill be explained hereinafter. In this embodiment, though two TFTs areexemplified as the semiconductor device, the semiconductor deviceincluded in a thin film circuit and a liquid crystal display apparatusis not limited to the two TFTs, any circuit device can be used. A memorydevice, a diode, a photoelectric conversion device, a resistive element,a coil, a capacitance element, an inductor, or the like can be typicallygiven as examples for the semiconductor device, in addition to TFTs.

[0076] As shown in FIG. 3A, a metal film 501 is deposited over a firstsubstrate 500 by sputtering. Here, tungsten is used for forming themetal film 501 and formed to have a thickness of from 10 to 200 nm,preferably, from 50 to 75 nm. In this embodiment, the metal film 501 isdeposited directly on the first substrate 500, but the metal film 501may also be deposited after covering the first substrate 500 by aninsulating film such as silicon oxide, silicon nitride, siliconoxynitride, or the like.

[0077] An oxide film 502 is deposited to be stacked after depositing themetal film 501 without exposing to the air. A silicon oxide film isdeposited to have a thickness of from 150 to 300 nm as the oxide film502. In case of depositing by sputtering, a film is deposited over theedge of the first substrate 500. Hence, the metal film 501 and the oxidefilm 502 are preferably removed selectively by O₂ ashing and the edge ofthe first substrate 500 is preferably cut by dicing to prevent the oxidefilm 502 from remaining over the first substrate 500 in separating in alater process.

[0078] In depositing the oxide film 502, pre-sputtering, that is, plasmais generated by shielding between a target and a substrate with shutter,is carried out as a preliminary step toward sputtering. The firstsubstrate 500 is pre-sputtered under the equilibrium state, that is, Arflow rate used is 10 sccm; O₂, 30 sccm; substrate temperature, 270° C.;and deposition power, 3 kW. A metal oxide film 503 is deposited havingan ultra thin thickness of several nm (here, 3 nm) between the metalfilm 501 and the oxide film 502 by the pre-sputtering. The metal oxidefilm 503 is formed by oxidization of the metal film 501. Hence, themetal oxide film 503 is formed of tungsten oxide.

[0079] The metal oxide film 503 is, but not exclusively, deposited bypre-sputtering in this embodiment. For example, the metal oxide film 503may be deposited by oxidizing deliberately the surface of the metal film501 in plasma using oxygen or oxygen added with inert gases such as Aror the like.

[0080] After depositing the oxide film 502, a base film 504 is depositedby plasma chemical vapor deposition (hereinafter, PCVD). Here, a siliconoxynitride film is deposited to have a thickness approximately of 100 nmas the base film 504. After depositing the base film 504, asemiconductor film 505 is deposited without exposing to the atmosphere.The semiconductor film 505 is formed to have a thickness of from 25 to100 nm, preferably, from 30 to 60 nm. The semiconductor film 505 may beeither an amorphous semiconductor or a polycrystalline semiconductor.The semiconductor film may be formed by not only silicon but alsosilicon germanium. In case of using silicon germanium, the concentrationof germanium is preferably approximately from 0.01 to 4.5 atomic %.

[0081] As shown in FIG. 3B, the semiconductor film 505 is crystallizedby a known technique. As the known technique, thermal crystallizationusing an electric heating furnace, laser crystallization using a laserlight, and ramp annealing crystallization using an infrared light.Alternatively, crystallization using catalytic elements can be usedaccording to the technique disclosed in Unexamined Patent PublicationNo. 7-130652.

[0082] The semiconductor film 505 that is a polycrystallinesemiconductor film may be formed in advance by sputtering, PCVD, orthermal CVD.

[0083] The semiconductor film 505 is crystallized by lasercrystallization in this embodiment. A crystal having a large graindiameter can be obtained by laser light irradiation of from a secondharmonic to a fourth harmonic of a fundamental wave by using a solidlaser capable of continuously oscillating. Typically, a second harmonic(532 nm) or a third harmonic (355 nm) of Nd: YVO₄ laser (fundamentalwave of 1064 nm) may be applied. When a continuously oscillating laseris used, a laser light emitted from the continuously oscillating YVO₄laser having an output power of 10 W is converted to a harmonic by anonlinear optical device. There is also a method in which a harmonic isoutputted by using nonlinear optical device. Preferably, the laser lightis formed by using an optical system such that it becomes in arectangular shape or an elliptical shape on an irradiating face andradiated to the semiconductor film 505. The laser irradiation is carriedat energy density of approximately from 0.01 to 100 MW/cm² (preferablyfrom 0.1 to 10 MW/cm²) and a scanning speed of approximately from 10 to2000 cm/s.

[0084] The laser crystallization may be carried out by radiating acontinuous wave laser light of fundamental wave and a continuous wavelaser light of harmonic wave, or radiating a continuous wave laser lightof fundamental wave and a pulsed laser light of harmonics.

[0085] A laser light may be radiated in an inert gas atmosphere such asrare gas or nitride. According to this, the surface roughness of asemiconductor due to a laser irradiation, further, the variations of athreshold value due to the variations of interface state density can beprevented.

[0086] A semiconductor film 506 that is enhanced its degree ofcrystallinity is formed by irradiating the above described semiconductorfilm 505 with a laser light. Next, as shown in FIG. 3C, thesemiconductor film 506 is patterned to form island like semiconductorfilms 507, 508. Various semiconductor devices as typified by TFTs areformed using the island like semiconductor films 507, 508. In thisembodiment, the base film 504 and the island like semiconductor films507, 508 are in contact with each other, but an electrode, an insulatingfilm, or the like may be formed between the base film 504 and the islandlike semiconductor films 507, 508 depending on a semiconductor device.For example, in case of a bottom gate type TFT that is one of thesemiconductor devices, a gate electrode and a gate insulating film areformed between the base film 504 and the island like semiconductor films507, 508.

[0087] In this embodiment, top gate type TFTs 509 and 510 are formedusing the island like semiconductor films 507, 508 (FIG. 3D).Specifically, a gate insulating film 511 is deposited so as to cover theisland like semiconductor films 507, 508. Then, a conductive film isdeposited over the gate insulating film 511 and patterned, and gateelectrodes 512, 513 are formed. Next, impurities imparting n-type areadded to the island like semiconductor films 507, 508 using the gateelectrodes 512, 513 or resist that is deposited and patterned as masksto form a source region, a drain region, and an LDD (Lightly DopedDrain) region. Here, TFTs 509, 510 are n-type, in case of using p-typeTFTs, impurities imparting p-type are added.

[0088] According to the above described process, TFTs 509, 510 can beformed. A method for manufacturing the TFTs is not limited to the abovedescribed process.

[0089] A first interlayer insulating film 514 is fabricated so as tocover the TFTs 509, 510. Contact holes are formed at the gate insulatingfilm 511 and the first interlayer insulating film 514, and terminals 515to 518 connected to the TFTs 509, 510 via the contact holes are formedso as to be in contact with the first interlayer insulating film 514.

[0090] A pixel electrode 540 of a liquid crystal cell is formed by atransparent conductive film such as ITO so as to be in contact with theterminal 515. Then, an orientation film 541 is formed to cover the pixelelectrode 540, and rubbing treatment is carried out to the orientationfilm 541. A part of the terminal 518 is exposed by etching or the likeso as not to be covered by the orientation film 541.

[0091] A protective layer 521 is formed over the orientation film 541.As a material for forming the protective layer 521, a material which canprotect the surface of the TFTs 509, 510, the orientation film 541, andterminals 515 to 518 in pasting or separating the second substrate in alater process, and which can be removed after separating a secondsubstrate is used. For example, the protective film 521 can be formed bycoating resin of epoxy series, acrylate series, or silicon series thatis soluble in water over the whole surface, and baking.

[0092] In this embodiment, a water-soluble resin (TOAGOSEI Co., Ltd.:VL-WSHL10) is spin-coated to have a thickness of 30 μm, and exposed fortwo minutes to be partially cured, then, exposed its back with UV raysfor 2.5 minutes, and then, exposed its surface for 10 minutes, that is,12.5 minutes in total, to be fully cured. Consequently, the protectivelayer 521 is formed (FIG. 3E).

[0093] Though an example that the protective layer 521 is formed afterthe orientation film 541 is formed is explained in this embodiment, theorientation film 541 may be formed after removing the protective layer521 in a later process. However, in case of stacking a plurality oforganic resins, there is a threat of melting the stacked organic resindepending on the solvent in coating or baking, or increasing excessivelyits density. In case of forming the protective layer 521 after formingthe orientation film 541, each of which is formed by organic resinsoluble in the same etchant, an inorganic insulating film (a SiN_(x)film, a SiN_(x)O_(y) film, an AlN_(x) film, or an AlN_(x)O_(y) film) ispreferably formed so as to cover the first interlayer insulating film514, and be disposed between the first interlayer insulating film 514and the terminals 515 to 518 for removing smoothly the protective film521 in a later process.

[0094] For separating smoothly in a later process, the metal oxide film503 is crystallized. By this crystallization, the metal oxide film 503becomes susceptible to fracture in grain boundary and enhanced itsbrittleness. The crystallization is carried out by heat-treating forapproximately at from 420 to 550° C. for from 0.5 to 5 hours.

[0095] Then, some treatments are carried out on the metal oxide film 503in order to make it easier for the metal oxide film 503 to be separatedby weakening partly the adhesiveness between the metal oxide film 503and the oxide film 502 or the adhesiveness between the metal oxide film503 and the metal film 501. Specifically, the periphery of the regionthat is to be separated is locally pressed from outside to be damaged apart of the inside or the boundary face-neighborhood of the oxide film503. Specifically, a hard needle such as a diamond pen is attachedperpendicular to the edge-neighborhood of the metal oxide film 503 andmoved along with the metal oxide film 503 with applying loading.Preferably, a scriber device can be used to move with applying loadingon the region with press force ranging from 0.1 to 2 mm. It is importantto carry out some treatment for easy separating, that is, it isimportant to prepare for separating process. Such preparatory process toweaken selectively the adhesiveness will prevent poor separating andimprove the process yield.

[0096] Next, a second substrate 523 is pasted onto the protective film521 with a two-sided tape 522, and a third substrate 525 is pasted overthe first substrate 500 with a twp-sided tape 524 (FIG. 4A). An adhesivecan be used instead of a two-sided tape. For example, it is possible toreduce the load of a semiconductor device, which becomes increased byseparating the second substrate, by using an adhesive that is meltedwith UV light.

[0097] The third substrate 525 prevents the first substrate 500 frombeing damaged in a later process for separating. For the secondsubstrate 523 and the third substrate 525, the substrate that has higherrigidity than that of the first substrate 500, for example, a quartzsubstrate or a semiconductor substrate is preferably to be used.

[0098] Then, the metal film 501 is separated from the oxide film 502 bya physical means. The separation of metal film 501 is started from theregion that is partly weakened its adhesiveness to the metal film 501 orthe oxide film 502 in the previous process.

[0099] The metal film 501 may be removed by separating the metal film501 from metal oxide film 503, by separating the oxide film 502 from themetal oxide film 503, or splitting the metal oxide film 503 into two.Further, the second substrate 523 to which semiconductor devices (here,TFTs 509, 510) are pasted is separated from the third substrate 525 towhich the first substrate 500 and the metal film 501 are pasted. Theseparation can be carried out with comparatively small force (forexample, man's hand, air pressure of gas sprayed from a nozzle,ultrasonic waves, or the like). FIG. 4B shows a state of afterseparating.

[0100] A first polarization plate 527 provided over a resin 533 isbonded to the oxide layer 502 that is partly attached with the metaloxide film 503 with an adhesive 526 (FIG. 4C). At this time, it isimportant that the material for the adhesive 526 is selected in orderthat the adhesiveness between the oxide layer 502 and the firstpolarization plate 527 by the adhesive 526 to be stronger than thatbetween the second substrate 523 and the protective layer 521 by thetwo-sided tape 522.

[0101] If the metal oxide film 503 is remained over the surface of theoxide film 502, the adhesiveness of the polarization plate 527 may getworse, so that the remained metal oxide film may be completely removedbefore bonding to the oxide film 502.

[0102] In case of using the semiconductor devices 509, 510 are used forthe thin film circuit, the semiconductor devices 509, 510 areunnecessary to be pasted to overlap with the first polarization plate527.

[0103] As the adhesive 526, various curing adhesives such as aphoto-curing adhesive, for example, a reaction-curing adhesive, athermal-curing adhesive, or a UV-curing adhesive, or an anaerobicadhesive can be used. More preferably, the adhesive 526 is given highthermal conductivity by means of mixing powder comprising silver,nickel, aluminum, or aluminum nitride, or filler.

[0104] In addition, reference numeral 530 denotes a wiring formed overthe device substrate 534. The wiring 530 is formed by coating copperwith solder, gold, or tin.

[0105] As shown in FIG 5A, the two-sided tape 522 and the secondsubstrate 523 are separated sequentially or simultaneously from theprotective layer 521. The two-sided tape 522 can be separatedsimultaneously with curing the adhesive 526 by using UV-curing adhesiveas the adhesive 526, and by using a tape or adhesive that is separatedby UV light as the two-sided tape 522.

[0106] As shown in FIG 5B, the protective film 521 is removed by watersince the protective film 521 is formed by a resin that is soluble inwater. In case that the remained protective film 521 causesdeterioration, the remained protective film 521 is preferably removed bycarrying out cleaning treatment or O₂ plasma treatment to the surface.

[0107] In this embodiment, tungsten is used for a material of the metalfilm 501, however, the present invention is not limited thereto. Anymaterial can be used as long as which includes metals that allows asubstrate to be separated by forming the metal oxide film 503 over thesurface of the material and crystallizing the metal oxide film 503. Forinstance, TiN, WN, Mo, or the like can be used in addition to tungsten.In case of using these alloys as the metal film, the optimal temperaturefor heat treatment to crystallize differs depending on the compositionratio of the metal film. On the basis of the fact, the heat treatmentcan be carried out at the temperature that has no adverse effects on themanufacturing process for a semiconductor device, and selection rangesof the manufacturing process become difficult to be restricted byadjusting the composition ratio of the metal film.

[0108] A liquid crystal cell is formed as illustrated in FIG. 6.

[0109] After the protective layer 521 is formed, a counter substrate 542that is formed separately is pasted with sealant 543. Filler may bemixed into the sealant. The counter substrate 542 has a thickness ofapproximately several hundreds μm, and is provided with a counterelectrode 543 formed by a transparent conductive film and an orientationfilm 544 that is rubbing treated. In addition, a color filter and ablack matrix (a shielding film) to prevent disclination may be formed.Further, a second polarization plate 545 is pasted onto the oppositeside of the counter electrode 543 on which the counter substrate 542 isformed.

[0110] Then, liquid crystal 546 is injected and encapsulated to completea panel 550. In addition, the way of injecting liquid crystal may bedispenser method or dip method. A spacer may be provided between thepixel electrode 540 and the counter electrode 543 for keeping cell gaps.The liquid crystal display apparatus is completed by connectingelectrically the terminal 518 to the wiring 530 provided with the devicesubstrate 534 by wire bonding method.

[0111] Then, a method for manufacturing a liquid crystal displayapparatus according to the invention, which is different from thatillustrated in FIGS. 3 to 6, will be explained. In this embodiment,though a TFT is exemplified as the semiconductor device, thesemiconductor device included in a thin film circuit and a liquidcrystal display apparatus is not limited to the TFT, any circuit devicecan be used. For example, a memory device, a diode, a photoelectricconversion device, a resistive element, a coil, a capacitance element,an inductor, or the like can be typically given, in addition to TFTs.

[0112] As shown in FIG. 7A, a metal film 1501 is deposited over a firstsubstrate 1500 by sputtering. Here, tungsten is used for forming themetal film 1501 and formed to have a thickness of from 10 to 200 nm,preferably, from 50 to 75 nm. In this embodiment, the metal film 1501 isdeposited directly on the first substrate 1500, but the metal film 1501may also be deposited after covering the first substrate 1500 by aninsulating film such as silicon oxide, silicon nitride, siliconoxynitride, or the like.

[0113] An oxide film 1502 composing the insulating film is deposited tobe stacked after depositing the metal film 1501 without exposing to theair. A silicon oxide film is deposited to have a thickness of from 150to 300 nm as the oxide film 1502. In case of depositing by sputtering, afilm is deposited over the edge of the first substrate 1500. Hence, themetal film 1501 and the oxide film 1502 are preferably removedselectively by O₂ ashing to prevent the oxide film 1502 from remainingover the first substrate 1500 in separating in a later process.

[0114] In depositing oxide film 1502, pre-sputtering, that is, plasma isgenerated by shielding between a target and a substrate with shutter, iscarried out as a preliminary step toward sputtering. The first substrate1500 is pre-sputtered under the equilibrium state, that is, Ar flow rateused is 10 sccm; O₂, 30 sccm; substrate temperature, 270° C.; anddeposition power, 3 kW. A metal oxide film 1503 is deposited having anultra thin thickness of several nm (here, 3 nm) between the metal film1501 and the oxide film 1502 by the pre-sputtering. The metal oxide film1503 is formed by oxidization of the metal film 1501. Hence, the metaloxide film 1503 is formed of tungsten oxide.

[0115] The metal oxide film 1503 is, but not exclusively, deposited bypre-sputtering in this embodiment. For example, the metal oxide film1503 may be deposited by oxidizing deliberately the surface of the metalfilm 1501 in plasma using oxygen or oxygen added with inert gases suchas Ar or the like.

[0116] After depositing the oxide film 1502, a base film 1504 composingthe insulating film is deposited by PCVD. Here, a silicon oxynitridefilm is deposited to have a thickness of approximately 100 nm as thebase film 1504. After depositing the base film 1504, a semiconductorfilm 1505 is deposited without exposing to the atmosphere. Thesemiconductor film 1505 is formed to have a thickness of from 25 to 100nm, preferably, from 30 to 60 nm. The semiconductor film 1505 may beeither an amorphous semiconductor or a polycrystalline semiconductor.The semiconductor film may be formed by not only silicon but alsosilicon germanium. In case of using silicon germanium, the concentrationof germanium is preferably approximately from 0.01 to 4.5 atomic %.

[0117] Next, the semiconductor film 1505 is crystallized by a knowntechnique. As the known technique, thermal crystallization using anelectric heating furnace, laser crystallization using a laser light, andramp annealing crystallization using an infrared light. Alternatively,crystallization using catalytic elements can be used according to thetechnique disclosed in Unexamined Patent Publication No. 7-130652.

[0118] The semiconductor film 1505 is crystallized by lasercrystallization in this embodiment. Before the laser crystallization,the semiconductor film is thermal-annealed at 500° C. for 1 hour toincrease resistance of the semiconductor film to laser. In thisembodiment, the heat treatment enhances the brittleness of the metaloxide film 1503 to make it easier for the first substrate 1500 to beseparated later. By this crystallization, the metal oxide film 1503becomes susceptible to fracture in grain boundary and enhanced itsbrittleness. The crystallization of the metal oxide film 1503 ispreferably carried out by heat-treating for approximately at from 420 to550° C. from 0.5 to 5 hours.

[0119] A crystal having a large grain diameter can be obtained by laserlight irradiation of from a second harmonic to a fourth harmonic of afundamental wave by using a solid laser capable of continuouslyoscillating. Typically, a second harmonic (532 nm) or a third harmonic(355 nm) of Nd: YVO₄ laser (fundamental wave of 1064 nm) may be applied.When a continuously oscillating laser is used, a laser light emittedfrom the continuously oscillating YVO₄ laser having an output power of10 W is converted to a harmonic by a nonlinear optical device. There isalso a method in which a harmonic is outputted by using a nonlinearoptical device. Preferably, the laser light is formed by using anoptical system such that it becomes in a rectangular shape or anelliptical shape when radiated to an irradiating face, and radiated tothe semiconductor film 1505. On this occasion, an energy density ofapproximately from 0.01 to 100 MW/cm² (preferably from 0.1 to 10 MW/cm²)is necessary and a semiconductor film may be irradiated with the laserlight while it is moved relatively thereto at a speed of approximatelyfrom 10 to 2000 cm/s.

[0120] The laser crystallization may be carried out by radiating acontinuous wave laser light of fundamental wave and a continuous wavelaser light of harmonic wave, or radiating a continuous wave laser lightof fundamental wave and a pulsed laser light of harmonics.

[0121] A laser light may be radiated in the inert gas atmosphere such asrare gas or nitride. According to this, the surface roughness of asemiconductor due to a laser irradiation, further, the variations of athreshold value due to the variations of interface state density can beprevented.

[0122] The crystallinity of the semiconductor film 1505 is furtherenhanced by the above described crystallization. The semiconductor film1505 that is a polycrystalline semiconductor film may be formed inadvance by sputtering, PCVD, thermal CVD, or the like.

[0123] Next, as shown in FIG. 7B, the semiconductor film 1505 ispatterned to form island like semiconductor films 1507, 1508. Varioussemiconductor devices as typified by TFTs are formed using the islandlike semiconductor films 1507, 1508. In this embodiment, the base film1504 and the island like semiconductor films 1507, 1508 are in contactwith each other, but an electrode, an insulating film, or the like maybe formed between the base film 1504 and the island like semiconductorfilms 1507, 1508 depending on a semiconductor device. For example, incase of a bottom gate type TFT that is one of the semiconductor devices,a gate electrode and a gate insulating film are formed between the basefilm 1504 and the island like semiconductor films 1507, 1508.

[0124] In this embodiment, top gate type TFTs 1509, 1510 are formedusing the island like semiconductor films 1507, 1508 (FIG. 7C).Specifically, a gate insulating film 1511 is deposited so as to coverthe island like semiconductor films 1507, 1508. Then, a conductive filmis deposited over the gate insulating film 1511 and patterned, and then,gate electrodes 1512, 1513 are formed. Next, impurities imparting n-typeare added to the gate electrodes 1507, 1508 using the gate electrodes1512, 1513 or resist that is deposited and patterned as masks to form asource region, a drain region, and an LDD (Lightly Doped Drain) region.Here, TFTs 1509, 1510 are n-type, but impurities imparting p-type areadded in case of using p-type TFTs.

[0125] According to the above described process, TFTs 1509, 1510 can beformed. A method for manufacturing the TFTs is not limited to the abovedescribed process.

[0126] A first interlayer insulating film 1514 is fabricated so as tocover the TFTs 1509, 1510. Contact holes are formed in the gateinsulating film 1511 and the first interlayer insulating film 1514, andterminals 1515 to 1518 connected to the TFTs 1509, 1510 via the contactholes are formed so as to be in contact with the first interlayerinsulating film 1514.

[0127] The TFT 1510 used as a switching element of the pixel portion ofthe liquid crystal display apparatus is electrically connected to theterminal 1518. A pixel electrode of a liquid crystal cell is formed bytransparent conductive film such as ITO so as to connect to the terminal1518. A spacer 1519 is formed by using an insulating film. Then, anorientation film 1520 is formed to cover the pixel electrode 1550, theterminal 1518, and the spacer 1519, and rubbing treatment is carried outthereto. In addition, the orientation film 1520 may be formed to overlapwith the thin film circuit.

[0128] Then, a sealant 1521 is formed to encapsulate liquid crystal. Asshown in FIG. 8A, liquid crystal 1522 is dropped in the region encircledby the sealant 1521. A counter substrate 1523 that is formed separatelyis pasted with sealant 1521. FIG. 8B is a view showing a state after thecounter substrate 1523 is pasted. Filler may be mixed into the sealant1521. The counter substrate 1523 has a thickness of approximatelyseveral hundreds μm, and is provided with a counter electrode 1524formed by a transparent conductive film and an orientation film 1526that is rubbing treated. In addition, a color filter and a black matrix(a shielding film) to prevent disclination may be formed. Further, asecond polarization plate 1527 is pasted onto the opposite side of thecounter electrode 1524 on which the counter substrate 1523 is formed.

[0129] The region where the counter electrode 1524, the liquid crystal1522, and the pixel electrode 1550 are overlapped each other correspondsto a liquid crystal cell 1528. When the liquid crystal cell 1528 iscompleted, a panel 1529 is also completed. In addition, though a thinfilm circuit 1530 is not overlapped with the counter substrate 1523, thethin film circuit 1530 may dare to be overlapped with the countersubstrate 1523. In this case, a resin may be filled between the countersubstrate and the thin film circuit to increase mechanical strength of aliquid crystal display apparatus.

[0130] In this embodiment, the liquid crystal is encapsulated bydispenser method (dropping method) though, the invention is not limitedthereto. The liquid crystal may be encapsulated by dipping method(pumping method) utilizing capillary phenomenon after pasting thecounter substrate onto the liquid crystal.

[0131] Next, as shown in FIG. 9A, a protective film 1531 is formed tocover the thin film circuit 1530 and the panel 1529. The protectivelayer 1531 is formed by a material that can protect the thin filmcircuit 1530 and the panel 1529 in pasting or separating a secondsubstrate 1533 later, and that can be removed after separating thesecond substrate 1533. For example, the protective film 1531 can beformed by coating resin of epoxy series, acrylate series, or siliconseries that is soluble in water over the whole surface.

[0132] In this embodiment, a water-soluble resin (TOAGOSEI Co., Ltd.:VL-WSHL10) is spin-coated to have a thickness of 30 μm, and exposed fortwo minutes to be partially cured, then, exposed its back with UV raysfor 2.5 minutes, and then, exposed its surface for 10 minutes to befully cured. Consequently, the protective layer 1531 is formed.

[0133] In case of stacking a plurality of organic resins, there is athreat of melting the stacked organic resin depending on the solvent incoating or baking, or increasing excessively its density. In case offorming simultaneously both the first interlayer insulating film 1514and the protective layer 1531, each of which is formed by organic resinsoluble in the same etchant, an inorganic insulating film (a SiN_(x)film, a SiN_(x)O_(y) film, an AlN_(x) film, or an AlN_(x)O_(y) film) ispreferably formed so as to cover the first interlayer insulating film1514.

[0134] Then, some treatments are carried out on the metal oxide film1503 in order to make it easier for the metal oxide film 1503 to beseparated by weakening partly the adhesiveness between the metal oxidefilm 1503 and the oxide film 1502 or the adhesiveness between the metaloxide film 1503 and the metal film 1501. Specifically, the periphery ofthe region that is to be separated is locally pressed from outside todamage a part of the inside or the boundary face-neighborhood of theoxide film 1503. Specifically, a hard needle such as a diamond pen isattached perpendicular to the edge-neighborhood of the metal oxide film1503 and moved along with the metal oxide film 1503 with applyingloading. Preferably, a scriber device can be used to move with applyingloading on the region with press force ranging from 0.1 to 2 mm. It isimportant to carry out some treatment for easy separating, that is, itis important to prepare for separating. Such preparatory process toweaken selectively the adhesiveness will prevent poor separating andimprove the process yield.

[0135] Next, a second substrate 1533 is pasted onto the protective layer1531 with a two-sided tape 1532, and a third substrate 1535 is pastedover the first substrate 1500 with a two-sided tape 1534. An adhesivecan be used instead of a two-sided tape. For example, it is possible toreduce the load of a semiconductor device, which is increased byseparating the second substrate, by using an adhesive that is meltedwith UV light. The third substrate 1535 prevents the destruction of thefirst substrate 1500 in the subsequent process of separating. For thesecond substrate 1533 and the third substrate 1535, the substrate thathas higher rigidity than that of the first substrate 1500, for example,a quartz substrate or a semiconductor substrate is preferably to beused.

[0136] Then, the metal film 1501 is separated from the oxide film 1502by a physical means. The separation of metal film 1501 is started fromthe region that is partly weakened its adhesiveness with respect to themetal film 1501 or the oxide film 1502 in the previous process.

[0137] Three separating portions may be resulted from the separation ofmetal film 1501, that is, the separating portion of the metal film 1501and metal oxide film 1503, the separating portion of the oxide film 1502and the metal oxide film 1503, or the separating portion within themetal oxide film 1503. Further, the second substrate 1533 on whichsemiconductor devices (here, TFTs 1509, 1510) are pasted is separatedfrom the third substrate 1535 on which the first substrate 1500 and themetal film 1501 are pasted. The separation can be carried out withcomparatively small force (for example, man's hand, air pressure of gassprayed from a nozzle, ultrasonic waves, or the like). FIG. 9B shows astate of after the separating process.

[0138] A device substrate 1540 is bonded with an adhesive 1539 to theoxide layer 1502 that is partly attached with the metal oxide film 1503(FIG. 10). At this time, it is important that the material for theadhesive 1539 is selected in order that the adhesiveness to be strongerbetween the oxide layer 1502 and the device substrate 1540 by theadhesive 1539 than that between the second substrate 1533 and theprotective layer 1531 by the two-sided tape 1532.

[0139] As the adhesive 1539, various curing adhesives such as aphoto-curing adhesive, for example, a reaction-curing adhesive, athermal-curing adhesive, or a UV-curing adhesive, or an anaerobicadhesive can be used. More preferably, the adhesive 1539 is given highthermal conductivity by means of mixing powder comprising silver,nickel, aluminum, or aluminum nitride, or filler.

[0140] If the metal oxide film 1503 is remained over the surface of theoxide film 1502, the adhesiveness of the device substrate 1540 may getworse, so that the remained metal oxide film may be completely removedby etching or the like before bonding to a printed wiring board.

[0141] As shown in FIG. 10, the two-sided tape 1532 and the secondsubstrate 1533 are separated sequentially or simultaneously from theprotective layer 1531. The two-sided tape 1532 can be separatedsimultaneously with curing the adhesive 1539 by using UV-curing adhesiveas the adhesive 1539, and by using a tape or adhesive that is separatedby UV light as the two-sided tape 1532.

[0142] As shown in FIG. 11A, the protective film 1531 is removed bywater since the protective film 1531 is formed by a resin that issoluble in water. In case that the remained protective film 1531 causesdeterioration, the remained protective film 1531 is preferably removedby carrying out cleaning treatment or O₂ plasma treatment to thesurface.

[0143] A terminal 1518, a wiring 1551 provided with the device substrate1540 are electrically connected each other by a wiring 1552 by wirebonding method, and a liquid crystal display apparatus is completed. Thewiring 1551 is completed, for example, by coating copper with gold ortin. In addition, a timing for connecting the terminal 1518 and thewiring 1551 is not limited to the above described one.

[0144] It can be considered that a liquid crystal display apparatus iscompleted in this state. However, according to this embodiment,mechanical strength of the liquid crystal display apparatus is enhancedby encapsulating the liquid crystal display apparatus by a sealingmember.

[0145] As shown in FIG. 11B, the thin film circuit 1530 and the panel1529 are covered with a resin 1542 and a cover member 1543 is providedto protect the thin film circuit 1530 and the panel 1529. In addition,the cover member 1543 is not always necessary to be provided, the devicesubstrate 1540 can be covered directly with a sealing member.

[0146] As material for the sealing member used for encapsulating theliquid crystal display apparatus, a material that is used in general canbe used. For instance, polymeric material such as polyester, acrylicacid, polyvinyl acetate, propylene, chloroethene, acrylonitrilebutadienestyrene resin, or polyethylene terephthalate can be used. The pixelportion of the liquid crystal display apparatus is exposed, or amaterial for the resin 1542 or a cover member 1543 is appropriatelyselected in encapsulating in order to pass light therethrough.

[0147] By encapsulating a liquid crystal display apparatus with asealing member, mechanical strength of the liquid crystal displayapparatus is enhanced, heat generated in the liquid crystal displayapparatus is radiated, and electromagnetic noises from adjacent circuitof external of the liquid crystal display apparatus can be rejected.

[0148] A plastic substrate can be used for the device substrate 1540,the cover member 1543, and the counter substrate 1523. As a plasticsubstrate, ARTON® containing norbornene resin with polar group by JSRCorporation can be used. In addition, a plastic substrate such aspolyethylene terephthalate (PET), polyether sulfone (PES), polyethylenenaphthalate (PEN), polycarbonate (PC), nylon, polyether ether ketone(PEEK), polysulfone (PSF), polyetherimide (PEI), polyalylate (PAR),polybutylene terephthalate (PBT), or polyimide can be used. It isdesired that the device substrate 1540 has high thermal conductivity ofapproximately from 2 to 30 W/mK to radiate heat generated in the liquidcrystal display apparatus.

[0149] In this embodiment, tungsten is used for a material of the metalfilm 1501, however, the present invention is not limited thereto. Anymaterial can be used as long as which includes metals that allows asubstrate to be separated by forming the metal oxide film 1503 over thesurface of the material and crystallizing the metal oxide film 1503. Forinstance, TiN, WN, Mo, or the like can be used in addition to tungsten.In case of using these alloys as the metal film, the optimal temperaturefor heat treatment to crystallize differs depending on the compositionratio of the metal film. On the basis of the fact, the heat treatmentcan be carried out at the temperature that has no adverse effects on themanufacturing process for a semiconductor device, and selection rangesof the manufacturing process become difficult to be restricted byadjusting the composition ratio of the metal film.

[0150] In addition, a semiconductor device used for an LED driver thinfilm circuit can be formed according to the above described method forforming a semiconductor device.

[0151] A material for a resin covering a light-emitting diode ispreferably and appropriately selected depending on the method for curinga first substrate, a second substrate, and an adhesive.

[0152] An example that a wiring formed over a device substrate iselectrically connected to a thin film circuit or an LED driver thin filmcircuit by flip chip method instead of wire bonding method will beexplained hereinafter.

[0153]FIG. 12A is a cross-sectional view of a thin film circuit or anLED driver thin film circuit, each of which is provided with solderballs.

[0154] As shown in FIG. 12A, a semiconductor device 301 is electricallyconnected to a wiring over a device substrate with a solder ball 302.The solder ball 302 is provided to the side of the device substrate ofthe semiconductor device 301 and connected to an electrode 303 that iselectrically connected to the semiconductor device 301. The electrode303 may be formed by a conductive film that is the same as that of agate electrode of a TFT in case that the semiconductor device is theTFT.

[0155]FIG. 12B is a cross-sectional view of the thin film circuit or theLED driver thin film circuit in which semiconductor devices are stackedby flip chip method. As shown in FIG. 12B, semiconductor devices 310 and311, each of which is provided to two layers, are stacked. A wiringprovided to a device substrate is electrically connected to thesemiconductor device 310 with a solder ball 312. In addition, thesemiconductor device 310 is electrically connected to the semiconductordevice 311 with a solder ball 313.

[0156]FIG. 12C is a view showing an example that a wiring formed over adevice substrate is connected to a solder ball. As shown in FIG. 12C, asolder ball 312 is connected to a wiring 321 directly connected to asemiconductor device 320.

[0157] In addition, flip chip method is effective for the case that thenumber of connections between a thin film circuit or an LED driver thinfilm circuit and a wiring is large, since a pitch between wirings can berelatively reserved large compared with wire bonding method.

[0158] A solder ball and a wiring over a device substrate can beconnected by various methods such as thermo-compression bonding andthermo-compression bonding with vibrations from ultrasonic wave. Anunder fill may fill interspace of thermo-compressed solder balls betweeneach other to improve the mechanical strength of connection portions orthe efficiency of radiation of heat generated in a thin film circuit. Anunder fill is not always necessary to be used, but it can prevent poorconnection due to stress occurred by mismatch of coefficient of thermalexpansion of a device substrate and a semiconductor device. Thecompression by applying ultrasonic wave can prevent poor connectioncompared with compression without ultrasonic wave. Especially, it iseffective for the case that the number of bumps used for connecting isat least approximately 300.

[0159] A wiring formed over a device substrate can be electricallyconnected to a thin film circuit or an LED driver thin film circuit invarious forms by combining the ways described with reference to FIGS.12A to 12C. In addition, a flip chip method and wire bonding method canbe combined for connecting.

[0160] An active matrix liquid crystal display apparatus is explained inthis embodiment though, a passive matrix liquid crystal displayapparatus can be adopted in the invention.

[0161] According to above described structure of the invention, a liquidcrystal display apparatus can be drastically reduced its thickness andweight without being damaged the mechanical strength. Applying a liquidcrystal display apparatus according to the invention to an electronicappliance, a space for using IC can be kept large and an electronicappliance can be sophisticated without preventing the electronicappliance from being lightweight and downsized. Especially, a liquidcrystal display apparatus according to the present invention is usefulfor a portable electronic appliance since usability thereof becomesimproved by reducing the weight and the size. According to theinvention, even when size of a pixel portion of a liquid crystal displayapparatus is increased, weight thereof is almost the same as that of aliquid crystal display apparatus using a conventional glass substrate.

EXAMPLES

[0162] Hereinafter, examples of the present invention will be explained.

Example 1

[0163] The case that the present invention is applied to a card astypified by an electronic card will be explained in this example.

[0164] The configuration of an electronic card according to this examplewill be explained with reference to FIGS. 13A to 13D. FIG. 13A is across-sectional view showing a device substrate 401 at the time that apanel is completed. FIG. 13B is a top surface view of the devicesubstrate illustrated in FIG. 13A. FIG. 13A shows the state that istaken along the line of A-A′.

[0165] The device substrate 401 illustrated in FIGS. 13A and 13B has aconcave portion 402 in which an LED 403 or a plurality of those isformed. An LED driver thin film circuit 404 is provided to the concaveportion 402. The LED 403 and the LED driver circuit are covered with aresin 407.

[0166] Reference numeral 415 denotes a panel, and 411 denotes a thinfilm circuit. The panel and the thin film circuit are formed separatelyand pasted onto the device substrate 401. The thin film circuit 411 hasan antenna coil 406. A wiring 405 formed over the device substrate 401is connected electrically to the antenna coil 406.

[0167]FIG. 13C is a cross-sectional view of a liquid crystal displayapparatus according to the invention at the time of completing anelectronic card. FIG. 13D is a top view showing a liquid crystal displayapparatus illustrated in FIG. 13C. FIG. 13C is a cross-sectional viewshowing FIG. 13D taken along the line B-B′.

[0168] An electronic card as illustrated in FIGS. 13C and 13D is coveredwith a cover member 420 so as to seal the panel 415 and the thin filmcircuit 411 formed over the device substrate with a resin 422. In thisembodiment, light emitted from the panel 415 is transmitted through aportion 421, but not exclusively, the cover member can be formed of amaterial that is transparent to light in order that light emitted frompanel 415 also passes through the area except the portion 421.

[0169] In this embodiment, the structure of an electronic card thatsupplies signal or power supply voltage by electromagnetic introductionusing an antenna coil is explained, however, the electronic card canhave the structure that supplies signal or power supply voltage by lightusing a light-emitting device or light sensor. Further, the electroniccard is not limited to a noncontact card. The electronic card may be acontact card that transmits directly signals to a terminal device via aterminal.

[0170] The electronic card can be used for various purposes such as acash card, a credit card, a prepaid card, an ID card used foridentification, and a commuter pass. If an electronic card is installedwith the liquid crystal display apparatus according to the invention,data of the electronic card can be displayed on a pixel portion.Further, the reliability of certification of identity can be improved bydisplaying a photograph of a face. If a photograph of a face is usedinstead of a picture for identity, resolution of at least approximatelyQVGA (320×240) is required.

Example 2

[0171] A method for manufacturing a plurality of liquid crystal displayapparatus from a large sized device substrate will be explained withreference to FIGS. 14A and 14B.

[0172] A shown in FIGS. 14A and 14B, in case of using a large sizeddevice substrate 601, a plurality of concave portions 603 is formed inareas 602, each of which is corresponding to each liquid crystal displayapparatus. LEDs 604 are provided in each concave portion 603. A wiringconnected electrically to the LED 604, an LED driver thin film circuit,a reflection film, or the like (all are not shown) are provided with theLEDs, and a resin 605 is filled with each concave portion 603 as shownin FIG. 14B.

[0173] A panel or a thin film circuit is formed and diced in accordancewith the method explained in the embodiment, and a plurality of liquidcrystal display apparatus can be manufactured from one device substrate.The dicing can be carried out either before or after forming the panelor the thin film circuit.

Example 3

[0174] In this embodiment, the example that an LED is connected to aflexible printed wiring board (FPC) and the FPC is connected to a wiringover a device substrate, instead that the LED is directly connected tothe wiring over a device substrate.

[0175]FIG. 15A is a top surface view of an FPC connected with an LED. AnLED 701 is connected to a lead 702 that is sandwiched by a plastic film703. A terminal 704 connected with the lead 702 is not covered with theplastic film 703 and is exposed.

[0176]FIG. 15B is a view showing the state that the LED 701 illustratedin FIG. 15A is pasted onto a concave portion 705 in the device substrate706. FIG. 15C is a view showing a reverse side of the device substrate706 illustrated in FIG. 15B.

[0177] In the device substrate 706, a wiring 707 is provided with areverse side of the concave portion 705. The LED 701 provided in theconcave portion 705 and the wiring 707 are electrically connected eachother by the lead 702.

[0178] The surface of the device substrate 706 provided with the wiring707 has a concave portion 710. The regions provided with the concaveportions 705, 710 are preferably not overlapped each other consideringthe intensity of the device substrate 706. A solar cell 708 and a drivercircuit 709 for controlling the driving of the solar cell 708 areprovided in the concave portion 710. The wiring 707 is electricallyconnected to the driver circuit 709.

[0179] According to the FPC, devices that are provided with both sidesof the device substrate are electrically connected each other. Thus, thedevice substrate can be utilized without waste.

[0180]FIG. 15D is a cross-sectional view of the concave portion 705taken along the dotted line A-A′. A metal reflection film 711 isdeposited over the surface of the concave portion 711. According to thisexample, microscopic irregularities are formed on the surface of thereflection film 711 by corroding and by sandblasting using emery, andlight emitted from the LED can be diffusely reflected and emitted evenlyto the pixel portion.

Example 4

[0181] A method for forming a device substrate having a concave portionwill be explained in this example.

[0182]FIG. 16A is a view showing a plastic substrate 801 having anopening portion 803 and a plastic substrate 802 that is planarized. Theplastic substrates 801 and 802 are pasted each other. Then, a devicesubstrate 805 having a concave portion 804 is formed in the region wherethe opening portion 803 overlaps with the plastic substrate 802 that isplanarized.

Example 5

[0183] An example that an area sensor is provided with an electroniccard utilizing a liquid crystal display according to the presentinvention.

[0184]FIG. 17A is a view showing that a tip of a finger presses a pixelportion 910 that serves not only as an image display portion but also asan area sensor. FIG. 17B is a view showing a cross-sectional view of thepixel portion 910 illustrated in FIG. 17A.

[0185] As shown in FIG. 17B, a device substrate 901 is formed to have aconcave portion 905. A reflection film 902 is formed over the surface ofthe concave portion 905. An LED 903 is provided in the concave portion905 and covered with a resin 904.

[0186] A TFT 906 for applying voltage to a liquid crystal 907 and aphoto diode 908 are provided over the device substrate 901. The TFT 906and the photo diode 908 are separately formed over different substrates,and separated to paste onto the device substrate 901.

[0187] Light emitted from the LED 903 is reflected by a finger 911 thatserves as a subject, and radiated to the photo diode 908. Then, imagedata of the finger 911 can be obtained.

Example 6

[0188] A liquid crystal display apparatus according to the presentinvention can be utilized for various electronic appliances. Especially,it is effective to use the liquid crystal display apparatus for portabletype electronic appliances since the usability thereof is drasticallyimproved by reducing the weight or the size.

[0189]FIG. 18A is a view showing a sheet-shaped cellular phonecomprising a main body 2101, a display unit 2103, a sound input unit2104, a sound output unit 2105, a switch 2106, an external connectionport 2107, or the like. An earphone 2108 prepared separately can beconnected to the cellular phone via the external connection port 2107. Atouch panel liquid crystal display apparatus having a sensor accordingto the present invention is used for the display unit 2103. A continuousstream of operation can be carried out by touching a touch paneloperation key 2109 displayed on the display unit 2103. A thin filmcircuit provided with the liquid crystal display apparatus according tothe invention can be used as various signal processing circuits providedin the main body 2101.

[0190]FIG. 18B is a view showing an electronic book comprising a mainbody 2201, a display unit 2202, an operation key 2203, and the like. Themain body 2201 can have a built-in modem. A liquid crystal displayapparatus having a sensor according to the present invention is used forthe display unit 2202. A thin film circuit provided with the liquidcrystal display apparatus according to the invention can be used asvarious signal processing circuits.

[0191]FIG. 18C is a view showing a wrist watch comprising 2301, adisplay unit 2302, a fastening 2303, and the like. A liquid crystaldisplay apparatus having a sensor according to the present invention isused for the display unit 2302. A thin film circuit provided with theliquid crystal display apparatus according to the invention can be usedas various signal processing circuits provided in the main body 2301.

[0192]FIG. 18D is a view showing a personal computer comprising a mainbody 2401, a display unit 2402, a touch panel key board 2403, a mouse2404, an external connection port 2405, a power source plug 2406, andthe like. A liquid crystal display apparatus having a sensor accordingto the present invention is used for the display unit 2402. A touchpanel liquid crystal display apparatus having a sensor according to thepresent invention is used for the touch panel keyboard 2403 and themouse 2404. A continuous stream of operation can be carried out bytouching the touch panel key board 2403 and the mouse 2404. A thin filmcircuit provided with the liquid crystal display apparatus according tothe invention can be used as various signal processing circuits.

[0193]FIG. 18E is a view showing a front glass viewing from the insideof a car. A front glass 2501 is pasted with a liquid crystal displayapparatus 2503 according to the present invention. A display unit 2502can display various pieces of information required by a driver. In FIG.18E, an example that the liquid crystal display apparatus according tothe invention is pasted onto the front glass is explained, but theliquid crystal display apparatus can be pasted onto a window glass ofside and back of a driver's seat. Further, the liquid crystal displayapparatus can be pasted onto either inside or outside of a car.

[0194]FIG. 18F is a view showing an electronic card comprising a mainbody 2601, a display unit 2602, a connection terminal 2603, and thelike. The pixel portion of the liquid crystal display apparatusaccording to the invention can be utilized as the display unit 2602. Athin film circuit provided with the liquid crystal display apparatusaccording to the invention can be used as various signal processingcircuits provide in the main body 2601.

[0195] Therefore the applicable range of the invention is extremelylarge, and the invention can be utilized for electronic appliances invarious fields. The electronic appliances described in this embodimentcan use any structure of liquid crystal structures described inEmbodiments 1 to 5.

Example 7

[0196] A measurement result of a first substrate side after separatingand a cross-section of an insulating film side by TEM will be describedin this example.

[0197] On a glass substrate, a W film is deposited to have a thicknessof 50 nm by sputtering, a silicon oxide film is deposited to have athickness of 200 nm by sputtering, a silicon oxynitride film isdeposited to have a thickness of 100 nm by PCVD, an amorphous siliconfilm is deposited by PCVD to have a thickness of 50 nm as asemiconductor film, sequentially. Thereafter, the resulted film isheat-treated at 500° C. for 1 hour, further, at 550° C. for 4 hours,then, separated by a physical means such as polytetrafluoroethylenetape. FIG. 19 is a TEM photograph showing the W film and an oxide layerat the substrate side. FIG. 20 is a TEM photograph showing an oxidelayer and a silicon oxide film at the semiconductor film side.

[0198] As shown in FIG. 19, a metal oxide film is inhomogeneouslyremained in contact with a metal film. As shown in FIG. 20, a metaloxide film is also inhomogeneously remained in contact with a metalfilm. According to both the TEM photographs, the facts are proved thatthe metal oxide film is split off by or separated at boundary faces ofboth sides, and that the metal oxide film is remained inhomogeneouslyadhered to the metal film and the silicon oxide film.

[0199] Therefore a quantity of the metal oxide film is attached to thedevice substrate side of the insulating film in the liquid crystaldisplay apparatus according to the present invention.

Example 8

[0200] A liquid crystal material used for separating a first substrateafter completing a liquid crystal display apparatus will be explained inthis example.

[0201]FIGS. 21A and 21B are cross-sectional views showing a liquidcrystal display apparatus according to this example. The liquid crystaldisplay apparatus illustrated in FIG. 21A is provided with a columnarshaped spacer 1401 in a pixel to enhance the adhesiveness of a countersubstrate 1402 and a polarizing plate 1403 at a device side. Accordingto this, a semiconductor device except that in the region that isoverlapped with a sealing member at the separation of the firstsubstrate can be prevented from remaining at the first substrate side.

[0202]FIG. 21B a cross-sectional view showing a liquid crystal displayapparatus utilizing a nematic liquid crystal, smectic liquid crystal,ferroelectric liquid crystal or PDLS (polymer dispersed liquid crystal)containing these liquid crystals in polymer resin. The adhesiveness ofthe counter substrate 1402 and the polarizing plate 1403 at a deviceside are enhanced, and a semiconductor device except that in the regionthat is overlapped with a sealing member at the separation of the firstsubstrate can be prevented from remaining at the first substrate side byusing PDLC 1404.

[0203] Although the present invention has been fully described by way ofexamples with reference to the accompanying drawings, it is to beunderstood that various changes and modifications will be apparent tothose skilled in the art. Therefore, unless otherwise such changes andmodifications depart from the scope of the present invention hereinafterdescribed, they should be construed as being included therein.

What is claimed is:
 1. A liquid crystal display apparatus comprising: afirst plastic substrate; a light-emitting device formed over the firstplastic substrate; a resin covering the light-emitting device; asemiconductor device formed on the insulating film; a liquid crystalcell electrically connected to the semiconductor device; and a secondplastic substrate, wherein the semiconductor device and the liquidcrystal cell are formed between the first plastic substrate and thesecond plastic substrate.
 2. A liquid crystal display apparatuscomprising: a first plastic substrate having a concave portion; alight-emitting device formed in the concave portion of the first plasticsubstrate; a resin formed in the concave portion to cover thelight-emitting device; an insulating film formed on the resin; asemiconductor device formed on the insulating film; a liquid crystalcell electrically connected to the semiconductor device; and a secondplastic substrate, wherein the semiconductor device and the liquidcrystal cell are formed between the first plastic substrate and thesecond plastic substrate.
 3. A liquid crystal display apparatuscomprising: a first plastic substrate; a metal film formed on the firstplastic substrate; a light-emitting device formed over the first plasticsubstrate; a resin covering the light-emitting device; an insulatingformed on the resin; a semiconductor device formed on the insulatingfilm; a liquid crystal cell electrically connected to the semiconductordevice; and a second plastic substrate, wherein the semiconductor deviceand the liquid crystal cell are formed between the first plasticsubstrate and the second plastic substrate.
 4. A liquid crystal displayapparatus comprising: a first plastic substrate having a concaveportion; a metal film and formed over the concave portion; alight-emitting device formed in the concave portion; a resin formed inthe concave portion to cover the light-emitting device; an insulatingfilm formed on with the resin; a semiconductor device formed on theinsulating film; a liquid crystal cell electrically connected to thesemiconductor device; and a second plastic substrate, wherein thesemiconductor device and the liquid crystal cell are formed between thefirst plastic substrate and the second plastic substrate.
 5. A liquidcrystal display apparatus according to any one of claims 3 and 4,wherein the metal film is sand blasted.
 6. A liquid crystal displayapparatus according to any one of claims 1 to 4, wherein the liquidcrystal cell is transparent to light.
 7. A liquid crystal displayapparatus according to claim 1, wherein the light-emitting device is alight-emitting diode.
 8. A liquid crystal display apparatus according toclaim 7, wherein the light-emitting diode is connected to an FPC andsupplied with current via the FPC.
 9. A liquid crystal display apparatusaccording to claim 2, wherein the light-emitting device is alight-emitting diode.
 10. A liquid crystal display apparatus accordingto claim 9, wherein the light-emitting diode is connected to an FPC andsupplied with current via the FPC.
 11. A liquid crystal displayapparatus according to claim 3, wherein the light-emitting device is alight-emitting diode.
 12. A liquid crystal display apparatus accordingto claim 11, wherein the light-emitting diode is connected to an FPC andsupplied with current via the FPC.
 13. A liquid crystal displayapparatus according to claim 4, wherein the light-emitting device is alight-emitting diode.
 14. A liquid crystal display apparatus accordingto claim 13, wherein the light-emitting diode is connected to an FPC andsupplied with current via the FPC.
 15. A cellular phone having theliquid crystal display apparatus according to any one of claims 1 to 4.16. An electronic book having the liquid crystal display apparatusaccording to any one of claims 1 to
 4. 17. A wrist watch having theliquid crystal display apparatus according to any one of claims 1 to 4.18. A personal computer having the liquid crystal display apparatusaccording to any one of claims 1 to
 4. 19. A front glass having theliquid crystal display apparatus according to any one of claims 1 to 4.20. An electronic card having the liquid crystal display apparatusaccording to any one of claims 1 to
 4. 21. A method for manufacturing aliquid crystal display apparatus comprising the steps of: formingsequentially a metal film, a metal oxide film, an insulating film, and asemiconductor film over either face of a first substrate; forming asemiconductor device by the semiconductor film; pasting a secondsubstrate with a first adhesive onto the first substrate to face thefirst substrate in such a way that the semiconductor device issandwiched therebetween; crystallizing the metal oxide film by heattreatment; separating the first substrate by splitting the metal oxidefilm into two, each of which is adhered to the metal film and theinsulating film; forming a light-emitting device over a plasticsubstrate and coating the plastic substrate with a resin so as to coverthe light-emitting device; pasting the semiconductor device onto theplastic substrate by bonding the insulating film adhered with a part ofthe metal oxide film to the resin with a third adhesive; separating thesecond substrate by removing the first adhesive; and forming a liquidcrystal cell electrically connected to the semiconductor device.
 22. Amethod for manufacturing a liquid crystal display apparatus comprisingthe steps of: forming sequentially a metal film, a metal oxide film, aninsulating film, and a semiconductor film over either face of a firstsubstrate; forming a semiconductor device by the semiconductor film;pasting a second substrate with a first adhesive onto the firstsubstrate to face the first substrate in such a way that thesemiconductor device is sandwiched therebetween; separating the firstsubstrate by splitting the metal oxide film into two, each of which isadhered to the metal film side and the insulating film side; forming alight-emitting device over a plastic substrate and coating the plasticsubstrate with a resin so as to cover the light-emitting device; pastingthe semiconductor device onto the plastic substrate by bonding theinsulating film adhered with a part of the metal oxide film to the resinwith a third adhesive; separating the second substrate by removing thefirst adhesive; forming a liquid crystal cell electrically connected tothe semiconductor device; and crystallizing the metal oxide film by heattreatment in forming the semiconductor device.
 23. A method formanufacturing a liquid crystal display apparatus comprising the stepsof: forming sequentially a metal film, a metal oxide film, an insulatingfilm, and a semiconductor film over either face of a first substrate;forming a semiconductor device by the semiconductor film; pasting asecond substrate with a first adhesive onto the first substrate to facethe first substrate in such a way that the semiconductor device issandwiched therebetween; crystallizing the metal oxide film by heattreatment; separating the first substrate by splitting the metal oxidefilm into two, each of which is adhered to the metal film side and theinsulating film side; forming a light-emitting device in a concaveportion of a plastic substrate and coating the concave portion with aresin so as to cover the light-emitting device; pasting thesemiconductor device onto the plastic substrate by bonding theinsulating film adhered with a part of the metal oxide film to the resinwith a third adhesive; separating the second substrate by removing thefirst adhesive; and forming a liquid crystal cell electrically connectedto the semiconductor device.
 24. A method for manufacturing a liquidcrystal display apparatus comprising the steps of: forming sequentiallya metal film, a metal oxide film, an insulating film, and asemiconductor film over either face of a first substrate; forming asemiconductor device by the semiconductor film; pasting a secondsubstrate with a first adhesive onto the first substrate to face thefirst substrate in such a way that the semiconductor device issandwiched therebetween; separating the first substrate by splitting themetal oxide film into two, each of which is adhered to the metal filmside and the insulating film side; forming a light-emitting device in aconcave portion of a plastic substrate and coating the concave portionwith a resin so as to cover the light-emitting device; pasting thesemiconductor device onto the plastic substrate by bonding theinsulating film adhered with a part of the metal oxide film to the resinwith a third adhesive; separating the second substrate by removing thefirst adhesive; forming a liquid crystal cell electrically connected tothe semiconductor device; and crystallizing the metal oxide film by heattreatment in forming the semiconductor device.
 25. A method formanufacturing a liquid crystal display apparatus comprising the stepsof: forming sequentially a metal film, a metal oxide film, an insulatingfilm, and a semiconductor film over either face of a first substrate;forming a semiconductor device by the semiconductor film; forming aliquid crystal cell which is electrically connected to the semiconductordevice; pasting a second substrate with a first adhesive onto the firstsubstrate to face the first substrate in such a way that thesemiconductor device and the liquid crystal cell are sandwichedtherebetween; crystallizing the metal oxide film by heat treatment;separating the first substrate by splitting the metal oxide film intotwo, each of which is adhered to the metal film side and the insulatingfilm side; forming a light-emitting device over a plastic substrate;coating the plastic substrate with a resin so as to cover thelight-emitting device; pasting the semiconductor device and the liquidcrystal cell onto the plastic substrate by bonding the insulating filmadhered with a part of the metal oxide film to the resin with a thirdadhesive; and separating the second substrate by removing the firstadhesive.
 26. A method for manufacturing a liquid crystal displayapparatus comprising the steps of: forming sequentially a metal film, ametal oxide film, an insulating film, and a semiconductor film overeither face of a first substrate; forming a semiconductor device by thesemiconductor film; forming a liquid crystal cell which is electricallyconnected to the semiconductor device; pasting a second substrate with afirst adhesive onto the first substrate to face the first substrate insuch a way that the semiconductor device and the liquid crystal cell aresandwiched therebetween; separating the first substrate by splitting themetal oxide film into two, each of which is adhered to the metal filmside and the insulating film side; forming a light-emitting device overa plastic substrate; coating the plastic substrate with a resin so as tocover the light-emitting device; pasting the semiconductor device andthe liquid crystal cell onto the plastic substrate by bonding theinsulating film adhered with a part of the metal oxide film to the resinwith a third adhesive; separating the second substrate by removing thefirst adhesive; and crystallizing the metal oxide film by heat treatmentin forming the semiconductor device.
 27. A method for manufacturing aliquid crystal display apparatus comprising the steps of: formingsequentially a metal film, a metal oxide film, an insulating film, and asemiconductor film over either face of a first substrate; forming asemiconductor device by the semiconductor film; forming a liquid crystalcell electrically connected to the semiconductor device; pasting asecond substrate with a first adhesive onto the first substrate to facethe first substrate in such a way that the semiconductor device and theliquid crystal cell are sandwiched therebetween; crystallizing the metaloxide film by heat treatment; separating the first substrate bysplitting the metal oxide film into two, each of which is adhered to themetal film side and the insulating film side; forming a light-emittingdevice in a concave portion of a plastic substrate and coating theconcave portion with a resin so as to cover the light-emitting device;pasting the semiconductor device and the liquid crystal cell onto theplastic substrate by bonding the insulating film adhered with a part ofthe metal oxide film to the resin with a third adhesive; and separatingthe second substrate by removing the first adhesive.
 28. A method formanufacturing a liquid crystal display apparatus comprising the stepsof: forming sequentially a metal film, a metal oxide film, an insulatingfilm, and a semiconductor film over either face of a first substrate;forming a semiconductor device by the semiconductor film; forming aliquid crystal cell which is electrically connected to the semiconductordevice; pasting a second substrate with a first adhesive onto the firstsubstrate to face the first substrate in such a way that thesemiconductor device and the liquid crystal cell are sandwichedtherebetween; separating the first substrate by splitting the metaloxide film into two, each of which is adhered to the metal film side andthe insulating film side; forming a light-emitting device in a concaveportion of a plastic substrate and coating the concave portion with aresin so as to cover the light-emitting device; pasting thesemiconductor device and the liquid crystal cell onto the plasticsubstrate by bonding the insulating film adhered with a part of themetal oxide film to the resin with a third adhesive; separating thesecond substrate by removing the first adhesive; and crystallizing themetal oxide film by heat treatment in forming the semiconductor device.29. A method for manufacturing a liquid crystal display apparatusaccording to any one of claims 21 to 28, wherein the liquid crystal cellis transparent to light.
 30. A method for manufacturing a liquid crystaldisplay apparatus according to claim 21, wherein the light-emittingdevice is a light-emitting diode.
 31. A method for manufacturing aliquid crystal display apparatus according to claim 30, wherein thelight-emitting diode is connected to an FPC and supplied with currentvia the FPC.
 32. A method for manufacturing a liquid crystal displayapparatus according to claim 22, wherein the light-emitting device is alight-emitting diode.
 33. A method for manufacturing a liquid crystaldisplay apparatus according to claim 32, wherein the light-emittingdiode is connected to an FPC and supplied with current via the FPC. 34.A method for manufacturing a liquid crystal display apparatus accordingto claim 23, wherein the light-emitting device is a light-emittingdiode.
 35. A method for manufacturing a liquid crystal display apparatusaccording to claim 34, wherein the light-emitting diode is connected toan FPC and supplied with current via the FPC.
 36. A method formanufacturing a liquid crystal display apparatus according to claim 24,wherein the light-emitting device is a light-emitting diode.
 37. Amethod for manufacturing a liquid crystal display apparatus according toclaim 36, wherein the light-emitting diode is connected to an FPC andsupplied with current via the FPC.
 38. A method for manufacturing aliquid crystal display apparatus according to claim 25, wherein thelight-emitting device is a light-emitting diode.
 39. A method formanufacturing a liquid crystal display apparatus according to claim 38,wherein the light-emitting diode is connected to an FPC and suppliedwith current via the FPC.
 40. A method for manufacturing a liquidcrystal display apparatus according to claim 26, wherein thelight-emitting device is a light-emitting diode.
 41. A method formanufacturing a liquid crystal display apparatus according to claim 40,wherein the light-emitting diode is connected to an FPC and suppliedwith current via the FPC.
 42. A method for manufacturing a liquidcrystal display apparatus according to claim 27, wherein thelight-emitting device is a light-emitting diode.
 43. A method formanufacturing a liquid crystal display apparatus according to claim 42,wherein the light-emitting diode is connected to an FPC and suppliedwith current via the FPC.
 44. A method for manufacturing a liquidcrystal display apparatus according to claim 28, wherein thelight-emitting device is a light-emitting diode.
 45. A method formanufacturing a liquid crystal display apparatus according to claim 44,wherein the light-emitting diode is connected to an FPC and suppliedwith current via the FPC.